A team of researchers at the University of Colorado in Boulder measured the metabolic burn of a dozen experienced barefoot/barely-shod runners and found that, contrary to current trends in running, running with lightweight shoes actually burned four percent less energy than running barefoot. The obvious caveats are that the study didn't look at injuries or strains due to wearing shoes, and that the shoes were super lightweight Nike Mayfly models, not your average pair. But it's worth considering if you're working to shave every last second off your race times, or to get a bit farther on your exercise runs. Photo by Making the Case for Running Shoes | NYTimes.com